Bleach-containing compositions for bleaching various surfaces, e.g., fabrics, are well known in the art. Amongst the different bleaching compositions available, those relying on bleaching by hypohalite bleach, such as hypochlorite, are often preferred, mainly for bleaching performance reasons.
It is desirable to add further ingredients to hypohalite bleach-containing compositions. Indeed, in order to improve the whitening performance of such bleaching compositions the addition of a brightener (also known as fluorescent whitening agent) can be beneficial. Furthermore, in order to improve the aesthetics of such bleaching compositions the addition of a dye or a pigment can be considered.
However, a drawback associated with the use of hypohalite bleach-containing compositions, e.g., hypochlorite-based compositions, is that certain further ingredients, added in addition to the hypohalite bleach, can be decomposed by the bleach. Indeed, hypohalite bleaches are oxidising agents and certain further ingredients can be prone to attacks and in some cases partial or even complete decomposition by such oxidising agents. Hence, certain further ingredients, such as certain brighteners, certain pigments and/or certain dyes, are difficult to incorporate in hypohalite bleach-containing compositions. Further ingredients that are prone to partial or even complete decomposition in hypohalite bleach-containing compositions are herein referred to as “bleach-unstable” ingredients. Whereas, further ingredients that are not prone to partial or even complete decomposition in hypohalite bleach-containing compositions are herein referred to as “bleach-stable” ingredients.
One way to avoid partial or even complete decomposition of further ingredients in hypohalite bleach-containing compositions is to carefully select bleach-stable ingredients for such hypohalite bleach-containing compositions. Indeed, when formulating a hypohalite bleach-containing composition, a bleach-stable brightener can be chosen over a bleach-unstable brightener. However, in some instances bleach-stable ingredients show an inferior performance or benefit when compared to their bleach-unstable counterparts. Indeed, especially the bleach-stable species of brighteners, pigments and dyes show a significantly inferior performance or benefit as compared to their bleach-unstable counterparts.
Another way of avoiding partial or even complete decomposition of further ingredients present in hypohalite bleach-containing compositions is to incorporate stabilization systems into the bleaching compositions. Indeed, it is known in the art to add to hypohalite bleach-containing compositions a radical scavenger or another stabilising agent in order to prevent or at least reduce the decomposition of further ingredients, in particular bleach-unstable ingredients, present in the bleaching compositions. For example, EP-A-0 668 345 and EP-A-1 001 010 describe bleaching compositions comprising a hypohalite bleach and a radical scavenger. However, even though such stabilization systems and especially radical scavengers are capable of stabilising certain further bleach-unstable ingredients, such as surfactants, it has been found that bleach-unstable brighteners, bleach-unstable pigments and/or bleach-unstable dyes are particularly prone to attacks by hypohalite bleaches and hence are extremely difficult to be stably incorporated into bleaching compositions comprising the known stabilization systems.
Indeed, although the systems described in the art provide stabilization of further bleach-unstable ingredients in hypohalite bleach-containing compositions, it has been found that the stabilization of bleach-unstable brighteners, bleach-unstable coloring-agents (such as pigments and/or dyes) may still be further improved. Indeed, especially the stabilization of such bleach-unstable brighteners, bleach-unstable coloring-agents (such as pigments and/or dyes) upon prolonged periods of storage (“upon storage”) may still be further improved.
It is therefore an objective of the present invention to provide a hypohalite bleach-containing bleaching composition comprising a compound selected from the group consisting of bleach-unstable brighteners, and bleach-unstable coloring-agents and mixtures thereof, wherein the decomposition of said compound is significantly reduced or even prevented.
It has now been found that this objective can be met by a liquid bleaching composition comprising a hypohalite bleach, a trimethoxy benzoic acid or a salt thereof and a compound selected from the group consisting of bleach-unstable brighteners, and bleach-unstable coloring-agents and mixtures thereof.
Advantageously, the bleaching composition as described herein also provides a significant reduction or even prevention of the decomposition of a compound selected from the group consisting of bleach-unstable brighteners, and bleach-unstable coloring-agents and mixtures thereof upon storage of said bleaching composition
A further advantage of the bleaching compositions according to the present invention is that they show an excellent bleaching performance.
In particular, the compositions of the present invention provide excellent bleaching performance when used in any laundry application (“fabric treatment applications”), e.g., as a laundry detergent, a laundry additive and/or a laundry pretreater.
Another advantage of the compositions of the present invention is that they are suitable for the cleaning of different types of fabrics including natural fabrics (e.g., fabrics made of cotton, viscose, linen, silk and wool), synthetic fabrics such as those made of polymeric fibers of synthetic origin as well as those made of both natural and synthetic fibers.
Yet another advantage of the bleaching compositions of the present invention is that said bleaching compositions are also suitable for the bleaching of different types of surfaces including hard-surfaces like floors, walls, tiles, glass, kitchen surfaces, bathrooms surfaces, toilet bowls and/or dishes and the like, in addition to the above mentioned fabric treatment applications.